Conventionally, a vehicle such as a minivan includes an automatic opening and closing apparatus for moving a slide door. The automatic opening and closing apparatus is placed at a lower side of a step panel which is provided at a lower part of an opening portion of the vehicle as a step panel when an occupant gets on or gets out the vehicle. Such automatic opening and closing apparatuses are disclosed, for example, in JP10-8828A and JP10-266697A. As illustrated in FIG. 8, the disclosed automatic opening and closing apparatuses include a drive pulley 52 and plural driven pulleys 53 and 54 at a lower surface of a step panel 51 and include a toothed belt 55 among pulleys 52, 53, and 54. The drive pulley 52 is driven by a drive unit such as a motor, or the like. The toothed belt 55 is connected to a slide door 58 via a connect portion 56. The slide door 58 is movable along a guide rail 57.
The opening portion of the vehicle is opened or closed by means of the slide door 58 by driving the drive pulley 52.
The toothed belt 55 is extending along a path defined by plural idle pulleys 59 and 60. The idle pulley 59 is provided so that the drive pulley 52 and the toothed belt 55 ensure the number of gears for mutual meshing. Accordingly, a driving force can efficiently be transmitted. The idle pulley 60 is arranged at the path intended by the toothed belt 55 so that the toothed belt 55 is prevented from flapping due to a vibration. The idle pulley 60 is provided for arranging the toothed belt 55 along the guide rail 57 through which the connect portion 56 is moved.
Positions of the idle pulleys 59 and 60 are defined such that a gear surface of the toothed belt 55 facing the idle pulleys 59 and 60 is not interfered therewith. More specifically, the toothed belt 55 requires a certain degree of flexibility for smooth operation. However, because the slide door 58 has a certain weight, the toothed belt 55 may occasionally be loosened as indicated by a chain double-dashed line in FIG. 8 when the slide door 58 is opened or closed. Therefore, the positions of the idle pulleys 59 and 60 are defined for ensuring a space S so that the upper located toothed belt 55 and the lower located toothed belt 55 do not in contact and interfere with each other. Further, a bracket 61 for supporting the idle pulley 60 is formed for preventing the loosened toothed belt 55 from being unhooked.
Regarding the automatic opening and closing apparatus having the aforementioned configuration, a request has been placed for narrowing a width (a width in a right and left direction in FIG. 8) for an arrangement of components on the vehicle side. However, as described above, the space is required for preventing an interference of the toothed belt 55 facing with each other when the toothed belt 55 is loosened. Therefore, downsizing of the automatic opening and closing apparatus in order to narrow the width of the whole automatic opening and closing apparatus may occasionally be difficult. Further, mountability of the automatic opening and closing apparatus relative to the vehicle may deteriorate and the arrangement of the components on the vehicle side may be limited.
A need thus exists to provide a slide door opening and closing apparatus for a vehicle, of which mountability and a degree of freedom in an arrangement of the components on a vehicle side can be improved.